cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A097750 Reversal of the binomial transform of the Whitney triangle A004070 (see A131250), triangle read by rows, T(n,k) for 0 <= k <= n.

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%I A097750 #27 Jan 26 2021 08:31:50
%S A097750 1,1,2,1,4,4,1,6,11,8,1,8,22,26,16,1,10,37,64,57,32,1,12,56,130,163,
%T A097750 120,64,1,14,79,232,386,382,247,128,1,16,106,378,794,1024,848,502,256,
%U A097750 1,18,137,576,1471,2380,2510,1816,1013,512,1,20,172,834,2517,4944,6476,5812,3797,2036,1024
%N A097750 Reversal of the binomial transform of the Whitney triangle A004070 (see A131250), triangle read by rows, T(n,k) for 0 <= k <= n.
%C A097750 Reversal of the Riordan array (1/(1-2x), x/(1-x)^2), see A131250. Row sums are A061667 and diagonal sums of A131250 are A045623. The n-th row elements correspond to the end elements of the 2n-th row of the Whitney triangle A004070. A131250 corresponds to the product of Pascal's triangle and the Whitney triangle.
%F A097750 T(n, k) = Sum_{i=0..n} binomial(n+k, i-k).
%F A097750 T(n, k) = T(n-1,k)+2*T(n-1,k-1)-T(n-2,k-2), T(0,0)=1, T(1,0)=1, T(1,1)=2, T(n,k)=0 if k<0 or if k>n. - _Philippe Deléham_, Jan 11 2014
%F A097750 T(n, k) = binomial(2*n-k, k)*hypergeom([1, 1, -k], [1, 1 - 2*k + 2*n], -1). - _Peter Luschny_, Oct 28 2018
%e A097750 Triangle begins:
%e A097750 1;
%e A097750 1, 2;
%e A097750 1, 4, 4;
%e A097750 1, 6, 11, 8;
%e A097750 1, 8, 22, 26, 16;
%e A097750 1, 10, 37, 64, 57, 32;
%e A097750 1, 12, 56, 130, 163, 120, 64;
%e A097750 1, 14, 79, 232, 386, 382, 247, 128;
%p A097750 T := (n,k) -> binomial(2*n-k, k)*hypergeom([1, 1, -k], [1, 1-2*k+2*n], -1):
%p A097750 for n from 0 to 8 do seq(simplify(T(n, k)), k=0..n) od; # _Peter Luschny_, Oct 28 2018
%t A097750 T[_, 0] = 1; T[n_, n_] := 2^n; T[n_, k_] /; 0 < k < n := T[n, k] = T[n - 1, k] + 2 T[n - 1, k - 1] - T[n - 2, k - 2]; T[_, _] = 0;
%t A097750 Table[T[n, k], {n, 0, 10}, {k, 0, n}] (* _Jean-François Alcover_, Jun 19 2019 *)
%Y A097750 Row sums are A061667.
%Y A097750 Cf. A004070, A097761, A131250.
%K A097750 easy,nonn,tabl
%O A097750 0,3
%A A097750 _Paul Barry_, Aug 23 2004
%E A097750 Definition and comments corrected by _Philippe Deléham_, Jan 11 2014